More than fifty years ago, the dreams of stargazers and the grand ambitions of a nation were realized when NASA astronaut Neil Armstrong crunched his left foot on lunar soil and became the first human to walk on the moon.

But before Armstrong could utter his famed phrase, “That’s one small step for (a) man, one giant leap for mankind,” and before the five subsequent missions to explore the moon would be possible, aerospace engineering had to move forward at a furious and daring pace in order to make the Apollo 11 mission possible. NASA had to make good on President John F. Kennedy’s promise in 1961 to transport people to the moon, a challenge that intensified when the Soviet Union bested the U.S. in the race to put the first man, woman and dog in space. The Soviets couldn’t win the moon, too.

Battling the clock, NASA and its contractors had to create and improvise machinery and technology to withstand the harsh conditions of space and the unique challenge of landing on and relaunching from the moon. Images of Armstrong and fellow astronaut Buzz Aldrin hopping around the lunar surface are just as remarkable now as they were on July 20, 1969. But for years, engineers back on Earth worked without fanfare to piece together the many components that would make the moon landing less of a miracle and more an achievement of science. Here are a few of their accomplishments.

A Powerful Thrust Was Needed to Reach the Moon

It can be argued that every mechanical component of Apollo 11 was an essential piece of the first mission to the moon. But without the thrust to push the spacecraft some 240,000 miles to the moon, and at least another 240,000 miles back home (distance depends on the moon’s orbit around Earth), a lunar mission would have remained a distant dream. Thanks to a heavy lift vehicle rocket called Saturn V, Apollo 11 had the power to travel 953,054 round-trip miles in eight days.

At 363 feet, Saturn V stood 60 feet taller than the Statue of Liberty. At 6.2 million pounds, including a big belly of fuel, the rocket weighed as much as 400 elephants before liftoff. The thrust it generated at launch — 7.6 million pounds — created 85 times more power than the Hoover Dam.

But three is the number that best illustrates the worth of Saturn V. Because most of the mission’s fuel would be needed for Apollo’s push out of Earth’s orbit, the spacecraft didn’t have to be heavy for the rest of the mission. NASA designed Saturn V to separate into three sections, each breaking off the main section as it expended its fuel. The first two stages fell into the ocean, but NASA isn’t sure where the third one went: either it stayed in space or hit the moon. The remainder of Apollo was relatively nimble, consisting of the command and service module (CSM) where astronauts would pilot the craft, as well as sleep and eat, and the lunar module (LM) that touched down on the moon.

With Saturn V serving as an ideal taxi to the moon, the five subsequent Apollo missions also relied on the three-stage propulsion system. It was used once more in 1973, carrying the Skylab space station into orbit.

Apollo Had Small but Strong Computing Power

Landing on the moon called for precision. Yet, NASA recognized it would be difficult from the mission control center to navigate Apollo onto the moving moon, so it got creative and designed two computerized guidance and navigation systems instead of one.

According to a history of the space agency’s computing systems, NASA installed separate computing systems on the CSM and LM. This had a twofold effect. If the command module system failed, Apollo astronauts could still find their way home because the on-board computer and its guidance system accepted data from the ground to aid with manual flight. If contact with mission control was lost, the system had autonomous return capability. Also, by having a separate computing system on the Apollo 11 lunar module, navigating a moon landing from the craft itself was more manageable than doing so from the CSM.

It’s long been noted that a single iPhone has more computing power than all that NASA had for each Apollo mission. But NASA’s computers had a feature that no modern consumer electronic product can claim. The computing system couldn’t — and didn’t — crash.

A Perfect Landing Set the Stage for More Exploration

With the three-section Saturn V shedding weight, and with separate computing systems making navigation easier, the stage was set for an eagle to take flight. Named “Eagle” for the Apollo 11 mission, the LM was designed, developed and built by Grumman Corporation, as were those for the next five missions.

The Apollo 11 lunar module featured an environmental control system that maintained the module interior temperature between 65 and 70 degrees Fahrenheit. It also had a landing radar and computer system that measured the delay between the microwaves from the moon’s surface so that it could calculate the distance for landing.

As the U.S. and other countries once again aim to explore the moon, some of the technological feats of the Apollo missions can be applied decades later. At a recent Universities Space Research Association conference, one expert suggested building a rocket like Saturn V. More tellingly, National Space Council Executive Director Scott Pace intimated that the successful aerospace engineering of the Apollo race proved that the current five-year timeline for the next mission to the moon could provide a “clarifying nature” to the hard work involved.

There is a lot to learn from what transpired on July 20, 1969. As millions watched on Earth, the Eagle landed four miles away from its predicted touchdown point but on a spot befitting the safe journey, the Sea of Tranquility. Years in the making, the U.S. had won the biggest prize of the space race, but Armstrong’s reflection about a giant leap was a reminder that this accomplishment was for everyone.

Interested in all things in outer space and exploration? We are, too. Take a look at open positions at Northrop Grumman and consider joining our team.